# Is it possible to run text through an external program?

• I guess this is a bit of how TextFX works and I suppose I’m asking “can I write my own TextFX-like filters” and have n++ send the selected text through the program and replace the text with its output

• The literal answer to your question is “yes.” I am assuming, however, that you’d also like to know how. :-)

Using the NppExec plugin, you can grab the selected text and pass it through another program, and then grab the results. Here is one where I had NppExec grab the entire contents of the given window, save it to a temporary file, pass it through gpg to decrypt it, and paste the contents back into that same NPP window.

cls
npp_save
cmd.exe /c exit %RANDOM%														// cannot access $(SYS.RANDOM) directly through NppExec, but can tell cmd.exe to return it as a value set tempfile =$(SYS.TEMP)\NppGpgFile_$(EXITCODE).tmp // create random tempfile name set ascfile =$(SYS.TEMP)\NppGpgFile_$(EXITCODE).asc // create associated ascfile name sci_sendmsg SCI_SELECTALL // select all sel_saveto$(ascfile) :a														// save selection to the ascfile	(use :a to save as ansi, to prevent unicode prefix ÿþ getting embedded)
gpg.exe --output "$(tempfile)" --decrypt "$(ascfile)"							// decrypt
sel_loadfrom $(tempfile) // replace selection with results sci_sendmsg SCI_DOCUMENTSTART // deselect rm -rf "$(tempfile)" "$(ascfile)" // cleanup temp files npp_save  Since you want to make use of what you’ve already selected, you wouldn’t need (for eample) the sci_sendmsg SCI_SELECTALL, because you would want to leave the selection alone. So, based on your description that it’s already selected, here’s something that should give you a starting place: cmd.exe /c exit %RANDOM% // cannot access$(SYS.RANDOM) directly through NppExec, but can tell cmd.exe to return it as a value
set destfile = $(SYS.TEMP)\NppFilterDestinatino_$(EXITCODE).tmp					// create random destfile name
set sourcefile = $(SYS.TEMP)\NppFilterSource_$(EXITCODE).tmp					// create associated sourcefile name
sel_saveto "$(sourcefile)" :a // save selection to the sourcefile (use :a to save as ansi, to prevent unicode prefix ÿþ getting embedded) c:\path\to\program.exe --output "$(destfile)" --source "$(sourcefile)" // this is the program you're filtering it through; this will work if your program can take input and output filenames at the command prompt // however, if your program only uses STDIN and STDOUT, then do something like: // type "$(sourcefile)" | c:\path\to\program.exe > "$(destfile)" // this uses windows pipes and redirection so your program.exe takes STDIN and outputs to STDOUT, but NppExec can interface with the files sel_loadfrom "$(destfile)"														// replace selection with results
rm -rf "$(destfile)" "$(sourcefile)"											// cleanup temp files


I left in the random file naming for the tempfiles, because it should keep collisions from occurring. I included options for either command-line arguments to your program.exe, or using windows type, along with an input pipe and output redirection, so that your program could use STDIN->STDOUT.